Updated May 2017
Are your base layers getting stinky? Since it might be time to re-up, we updated this review as of May 2017, adding helpful comparison charts and graphs to aid you with your decision. We also analyzed the current market to ensure that our Editors' Choice winner still earns top honors.
Best Overall Pair of Long Underwear
SmartWool NTS Mid 250
Warm for the weight
Dries relatively slowly
Throughout our many tests, a clear winner became obvious. Merino wool and more specifically the Smartwool NTS Mid 250
, had significant advantages over competitors, making it a favorite and our Editors' Choice. Combining a stylish construction with craftsmanship that added comfort, it was a piece we could quickly forget we were wearing (in a good way). The slim-fit waist helped it stay in place during activity, and the wool's gentle stretch added to our ability to move unencumbered. In cold temps, the NTS was our first layer, and it worked well on its own in warmer conditions. While some contenders were better suited for a particular use, if we could only have one base layer, the NTS Mid 250 would be it.
Read full review: Smartwool NTS Mid 250
Best Bang for the Buck
The North Face Warm
Solid all around
Not very warm
Average drying speed
Looking at some of the prices in the base layer marketplace, you might be wondering if it's possible to purchase an effective base layer that doesn't break the bank. The answer lies in The North Face Warm
. From the moment we slipped into this smooth operator, we were impressed by its comfort. It doesn't itch but rather caresses your torso. It's capable when layering over and under this model, and it breathes sufficiently, too. We were psyched on this product's durability, with bomber seams and solid synthetic fabric. It didn't regulate temperature as well as some of the merino wool and blended fabric products, but we found it suitable to a range of activities and temperatures. For exceptional value in a base layer that is built to last several seasons, we recommend our Best Buy award winner, the Warm from The North Face.
Read full review: The North Face Warm
Top Pick for Lightweight
Rab Merino+ 160
Fastest drying model
Not very warm
In our field of competitors, there wasn't a lightweight model that performed nearly as well as the Rab Merino+ 160
, which only weighs 7.5 oz. This product of blended merino wool and polyester rocked the boat in several categories, giving new inspiration to what thinner, lighter base layers are capable of. It has an excellent fit, feels great, layers surprisingly well, and breathes like a mechanical lung. Most impressively, this was the fastest-drying fabric in the group of competitors. Being so thin, it didn't provide much durability or warmth. Our reviewers and friends also agreed that this model is good to go for social environments as well. However, if you're looking for the best combination of performance and low weight for use in mostly cool temperatures, or cold weather as a first layer, our Top Pick for Lightweight award winner offers just that.
Read full review: Rab Merino+ 160